The invention relates to apparatus for resurfacing automotive valves, and more particularly to chuck assemblies for such apparatus.
A typical valve resurfacing apparatus includes a chuck assembly for rotating a valve about its longitudinal axis, and a grinding wheel for resurfacing the valve. See, for example, U.S. Pat. No. 4,228,621, issued Oct. 21, 1980.
If the chuck assembly does not rotate the valve exactly about its longitudinal axis, i.e., if the axis of rotation of the valve is not coincident with the longitudinal axis of the valve, the end of the valve will wobble. This is known as "run-out." Known chuck assemblies for use in valve resurfacing have run-out of at least 0.0006 to 0.0009 inches.
Also, known chuck assemblies tend to wear out relatively quickly. When these chuck assemblies wear out, the critical parts must be returned to the manufacturer to be rebuilt.